//! 3d testbed
//!
//! You can switch scene by pressing the spacebar

mod helpers;

use bevy::prelude::*;
use helpers::Next;

fn main() {
    let mut app = App::new();
    app.add_plugins((DefaultPlugins,))
        .init_state::<Scene>()
        .add_systems(OnEnter(Scene::Light), light::setup)
        .add_systems(OnEnter(Scene::Bloom), bloom::setup)
        .add_systems(OnEnter(Scene::Gltf), gltf::setup)
        .add_systems(OnEnter(Scene::Animation), animation::setup)
        .add_systems(OnEnter(Scene::Gizmos), gizmos::setup)
        .add_systems(
            OnEnter(Scene::GltfCoordinateConversion),
            gltf_coordinate_conversion::setup,
        )
        .add_systems(Update, switch_scene)
        .add_systems(Update, gizmos::draw_gizmos.run_if(in_state(Scene::Gizmos)))
        .add_systems(
            Update,
            gltf_coordinate_conversion::draw_gizmos
                .run_if(in_state(Scene::GltfCoordinateConversion)),
        );

    #[cfg(feature = "bevy_ci_testing")]
    app.add_systems(Update, helpers::switch_scene_in_ci::<Scene>);

    app.run();
}

#[derive(Debug, Clone, Eq, PartialEq, Hash, States, Default)]
enum Scene {
    #[default]
    Light,
    Bloom,
    Gltf,
    Animation,
    Gizmos,
    GltfCoordinateConversion,
}

impl Next for Scene {
    fn next(&self) -> Self {
        match self {
            Scene::Light => Scene::Bloom,
            Scene::Bloom => Scene::Gltf,
            Scene::Gltf => Scene::Animation,
            Scene::Animation => Scene::Gizmos,
            Scene::Gizmos => Scene::GltfCoordinateConversion,
            Scene::GltfCoordinateConversion => Scene::Light,
        }
    }
}

fn switch_scene(
    keyboard: Res<ButtonInput<KeyCode>>,
    scene: Res<State<Scene>>,
    mut next_scene: ResMut<NextState<Scene>>,
) {
    if keyboard.just_pressed(KeyCode::Space) {
        info!("Switching scene");
        next_scene.set(scene.get().next());
    }
}

mod light {
    use std::f32::consts::PI;

    use bevy::{
        color::palettes::css::{DEEP_PINK, LIME, RED},
        prelude::*,
    };

    const CURRENT_SCENE: super::Scene = super::Scene::Light;

    pub fn setup(
        mut commands: Commands,
        mut meshes: ResMut<Assets<Mesh>>,
        mut materials: ResMut<Assets<StandardMaterial>>,
    ) {
        commands.spawn((
            Mesh3d(meshes.add(Plane3d::default().mesh().size(10.0, 10.0))),
            MeshMaterial3d(materials.add(StandardMaterial {
                base_color: Color::WHITE,
                perceptual_roughness: 1.0,
                ..default()
            })),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            Mesh3d(meshes.add(Cuboid::default())),
            MeshMaterial3d(materials.add(StandardMaterial {
                base_color: DEEP_PINK.into(),
                ..default()
            })),
            Transform::from_xyz(0.0, 1.0, 0.0),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            PointLight {
                intensity: 100_000.0,
                color: RED.into(),
                shadows_enabled: true,
                ..default()
            },
            Transform::from_xyz(1.0, 2.0, 0.0),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            SpotLight {
                intensity: 100_000.0,
                color: LIME.into(),
                shadows_enabled: true,
                inner_angle: 0.6,
                outer_angle: 0.8,
                ..default()
            },
            Transform::from_xyz(-1.0, 2.0, 0.0).looking_at(Vec3::new(-1.0, 0.0, 0.0), Vec3::Z),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            DirectionalLight {
                illuminance: light_consts::lux::OVERCAST_DAY,
                shadows_enabled: true,
                ..default()
            },
            Transform {
                translation: Vec3::new(0.0, 2.0, 0.0),
                rotation: Quat::from_rotation_x(-PI / 4.),
                ..default()
            },
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            Camera3d::default(),
            Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
            DespawnOnExit(CURRENT_SCENE),
        ));
    }
}

mod bloom {
    use bevy::{core_pipeline::tonemapping::Tonemapping, post_process::bloom::Bloom, prelude::*};

    const CURRENT_SCENE: super::Scene = super::Scene::Bloom;

    pub fn setup(
        mut commands: Commands,
        mut meshes: ResMut<Assets<Mesh>>,
        mut materials: ResMut<Assets<StandardMaterial>>,
    ) {
        commands.spawn((
            Camera3d::default(),
            Tonemapping::TonyMcMapface,
            Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
            Bloom::NATURAL,
            DespawnOnExit(CURRENT_SCENE),
        ));

        let material_emissive1 = materials.add(StandardMaterial {
            emissive: LinearRgba::rgb(13.99, 5.32, 2.0),
            ..default()
        });
        let material_emissive2 = materials.add(StandardMaterial {
            emissive: LinearRgba::rgb(2.0, 13.99, 5.32),
            ..default()
        });

        let mesh = meshes.add(Sphere::new(0.5).mesh().ico(5).unwrap());

        for z in -2..3_i32 {
            let material = match (z % 2).abs() {
                0 => material_emissive1.clone(),
                1 => material_emissive2.clone(),
                _ => unreachable!(),
            };

            commands.spawn((
                Mesh3d(mesh.clone()),
                MeshMaterial3d(material),
                Transform::from_xyz(z as f32 * 2.0, 0.0, 0.0),
                DespawnOnExit(CURRENT_SCENE),
            ));
        }
    }
}

mod gltf {
    use bevy::prelude::*;

    const CURRENT_SCENE: super::Scene = super::Scene::Gltf;

    pub fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
        commands.spawn((
            Camera3d::default(),
            Transform::from_xyz(0.7, 0.7, 1.0).looking_at(Vec3::new(0.0, 0.3, 0.0), Vec3::Y),
            EnvironmentMapLight {
                diffuse_map: asset_server.load("environment_maps/pisa_diffuse_rgb9e5_zstd.ktx2"),
                specular_map: asset_server.load("environment_maps/pisa_specular_rgb9e5_zstd.ktx2"),
                intensity: 250.0,
                ..default()
            },
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            DirectionalLight {
                shadows_enabled: true,
                ..default()
            },
            DespawnOnExit(CURRENT_SCENE),
        ));
        commands.spawn((
            SceneRoot(asset_server.load(
                GltfAssetLabel::Scene(0).from_asset("models/FlightHelmet/FlightHelmet.gltf"),
            )),
            DespawnOnExit(CURRENT_SCENE),
        ));
    }
}

mod animation {
    use std::{f32::consts::PI, time::Duration};

    use bevy::{prelude::*, scene::SceneInstanceReady};

    const CURRENT_SCENE: super::Scene = super::Scene::Animation;
    const FOX_PATH: &str = "models/animated/Fox.glb";

    #[derive(Resource)]
    struct Animation {
        animation: AnimationNodeIndex,
        graph: Handle<AnimationGraph>,
    }

    pub fn setup(
        mut commands: Commands,
        asset_server: Res<AssetServer>,
        mut graphs: ResMut<Assets<AnimationGraph>>,
    ) {
        let (graph, node) = AnimationGraph::from_clip(
            asset_server.load(GltfAssetLabel::Animation(2).from_asset(FOX_PATH)),
        );

        let graph_handle = graphs.add(graph);
        commands.insert_resource(Animation {
            animation: node,
            graph: graph_handle,
        });

        commands.spawn((
            Camera3d::default(),
            Transform::from_xyz(100.0, 100.0, 150.0).looking_at(Vec3::new(0.0, 20.0, 0.0), Vec3::Y),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            Transform::from_rotation(Quat::from_euler(EulerRot::ZYX, 0.0, 1.0, -PI / 4.)),
            DirectionalLight {
                shadows_enabled: true,
                ..default()
            },
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands
            .spawn((
                SceneRoot(asset_server.load(GltfAssetLabel::Scene(0).from_asset(FOX_PATH))),
                DespawnOnExit(CURRENT_SCENE),
            ))
            .observe(pause_animation_frame);
    }

    fn pause_animation_frame(
        scene_ready: On<SceneInstanceReady>,
        children: Query<&Children>,
        mut commands: Commands,
        animation: Res<Animation>,
        mut players: Query<(Entity, &mut AnimationPlayer)>,
    ) {
        for child in children.iter_descendants(scene_ready.entity) {
            if let Ok((entity, mut player)) = players.get_mut(child) {
                let mut transitions = AnimationTransitions::new();
                transitions
                    .play(&mut player, animation.animation, Duration::ZERO)
                    .seek_to(0.5)
                    .pause();

                commands
                    .entity(entity)
                    .insert(AnimationGraphHandle(animation.graph.clone()))
                    .insert(transitions);
            }
        }
    }
}

mod gizmos {
    use bevy::{color::palettes::css::*, prelude::*};

    pub fn setup(mut commands: Commands) {
        commands.spawn((
            Camera3d::default(),
            Transform::from_xyz(-1.0, 2.5, 6.5).looking_at(Vec3::ZERO, Vec3::Y),
            DespawnOnExit(super::Scene::Gizmos),
        ));
    }

    pub fn draw_gizmos(mut gizmos: Gizmos) {
        gizmos.cube(
            Transform::from_translation(Vec3::X * -1.75).with_scale(Vec3::splat(1.25)),
            RED,
        );
        gizmos
            .sphere(Isometry3d::from_translation(Vec3::X * -3.5), 0.75, GREEN)
            .resolution(30_000 / 3);

        // 3d grids with all variations of outer edges on or off
        for i in 0..8 {
            let x = 1.5 * (i % 4) as f32;
            let y = 1.0 * (0.5 - (i / 4) as f32);
            let mut grid = gizmos.grid_3d(
                Isometry3d::from_translation(Vec3::new(x, y, 0.0)),
                UVec3::new(5, 4, 3),
                Vec3::splat(0.175),
                Color::WHITE,
            );
            if i & 1 > 0 {
                grid = grid.outer_edges_x();
            }
            if i & 2 > 0 {
                grid = grid.outer_edges_y();
            }
            if i & 4 > 0 {
                grid.outer_edges_z();
            }
        }
    }
}

mod gltf_coordinate_conversion {
    use bevy::{
        color::palettes::basic::*, gltf::GltfLoaderSettings, prelude::*, scene::SceneInstanceReady,
    };

    const CURRENT_SCENE: super::Scene = super::Scene::GltfCoordinateConversion;

    pub fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
        commands.spawn((
            Camera3d::default(),
            Transform::from_xyz(-4.0, 4.0, -5.0).looking_at(Vec3::ZERO, Vec3::Y),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            DirectionalLight {
                color: BLUE.into(),
                ..default()
            },
            Transform::IDENTITY.looking_to(Dir3::Z, Dir3::Y),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            DirectionalLight {
                color: RED.into(),
                ..default()
            },
            Transform::IDENTITY.looking_to(Dir3::X, Dir3::Y),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands.spawn((
            DirectionalLight {
                color: GREEN.into(),
                ..default()
            },
            Transform::IDENTITY.looking_to(Dir3::NEG_Y, Dir3::X),
            DespawnOnExit(CURRENT_SCENE),
        ));

        commands
            .spawn((
                SceneRoot(asset_server.load_with_settings(
                    GltfAssetLabel::Scene(0).from_asset("models/Faces/faces.glb"),
                    |s: &mut GltfLoaderSettings| {
                        s.use_model_forward_direction = Some(true);
                    },
                )),
                DespawnOnExit(CURRENT_SCENE),
            ))
            .observe(show_aabbs);
    }

    pub fn show_aabbs(
        scene_ready: On<SceneInstanceReady>,
        mut commands: Commands,
        children: Query<&Children>,
        meshes: Query<(), With<Mesh3d>>,
    ) {
        for child in children
            .iter_descendants(scene_ready.entity)
            .filter(|&e| meshes.contains(e))
        {
            commands.entity(child).insert(ShowAabbGizmo {
                color: Some(BLACK.into()),
            });
        }
    }

    pub fn draw_gizmos(mut gizmos: Gizmos) {
        gizmos.axes(Transform::IDENTITY, 1.0);
    }
}
